N-Acyl-piperidone ketal compounds and their use as antidotes for protecting crop plants from herbicidal damage

ABSTRACT

N-Acyl-piperidone ketal compounds of the formula ##STR1## in which R 1  represents alkyl or halogen, 
     R 2  represents halogen, 
     R 3  represents alkyl and 
     R 4  represents alkyl, or 
     R 3  and R 4  together represent an optionally branched alkylene chain, and 
     R 5 , R 6 , R 7  and R 8  independently of one another represent hydrogen or alkyl, 
     and their use as antidotes for protecting crop plants from herbicidal damage.

This is a continuation of Ser. No. 166,281 filed 7/7/80, now abandoned.

This invention relates to certain new N-acyl-piperidone ketal compoundsand to their use as antidotes for protecting crop plants from herbicidaldamage, especially by herbicidally active thiolcarbamates andacetanilides. The invention further relates to new active compoundcombinations of the N-acyl-piperidone ketal compounds and certainherbicidally active carbamates and acetanilides which have particularlygood selective herbicidal properties.

"Antidotes" ("safeners") in the present connection are to be understoodas substances which are capable of specifically antagonising the harmfuleffects of herbicides on crop plants, that is to say of protecting thecrop plants, without thereby noticeably influencing the herbicidalaction on the weeds to be combated.

It is known that, when used for combating weeds in maize and othercrops, certain thiolcarbamates and acetanilides cause damage to the cropplants to a greater or lesser extent. It is furthermore known that suchcompounds as, for example, N-dichloroacetyl-2-ethylpiperidine andN-dichloroacetyl-cis/trans-decahydroquinoline are suitable for reducingdamage to crop plants by thiolcarbamates or acetanilides (see DE-OS(German Published Specification) 2,218,097). However, the activity ofthese substances as antidotes is not always completely satisfactory.

The present invention now provides, as new compounds, theN-acyl-piperidone ketals of the general formula ##STR2## in which R¹represents alkyl or halogen,

R² represents halogen,

R³ represents alkyl and

R⁴ represents alkyl, or

R³ and R⁴ together represent an optionally branched alkylene chain, and

R⁵, R⁶, R⁷ and R⁸ independently of one another represent hydrogen oralkyl.

The invention also provides a process for the preparation of anN-acyl-piperidone ketal of the formula (I) in which

(a) a piperidone ketal of the general formula ##STR3## in which R³, R⁴,R⁵, R⁶, R⁷ and R⁸ have the meanings indicated above,

is reacted with an alkanoyl chloride of the general formula ##STR4## inwhich R¹ and R² have the meanings indicated above,

if appropriate in the presence of a diluent and if appropriate in thepresence of an acid-binding agent, or

(b) an N-acyl-piperidone of the general formula ##STR5## in which R¹,R², R⁵, R⁶, R⁷ and R⁸ have the meanings indicated above,

is reacted with an alcohol of the general formula

    R.sup.9 --OH                                               (V),

in which

R⁹ represents alkyl or ω-hydroxyalkyl,

in the presence of a catalyst or of a water-binding agent, and ifappropriate in the presence of a diluent.

It has been found that N-acyl-piperidone ketals of the formula (I) areoutstandingly suitable for protecting crop plants from damage byherbicidally active thiolcarbamates or by herbicidally activeacetanilides.

It has also been found that the new active compound combinationscomprising an N-acyl-piperidone ketal of the formula (I) and at leastone herbicidally active thiolcarbamate and/or at least one herbicidallyactive acetanilide are outstandingly suitable for selectively combatingweeds in crops of useful plants.

Surprisingly, herbicidal damage to crop plants by thiolcarbamates or byacetanilides is better suppressed when N-acyl-piperidone ketals of theformula (I) are also used that when the known compoundsN-dichloroacetyl-2-ethyl-piperidine andN-dichloroacetyl-cis/trans-decahydroquinoline, which are chemicallysimilar substances of the same type of action, are employed. Moreover,it was not to be expected that the active compound combinationsaccording to the invention have better selective herbicidal propertiesthan active compound combinations which consist of at least oneherbicidally active thiolcarbamate or at least one herbicidally activeacetanilide and N-dichloroacetyl-2-ethyl-piperidine, which is known asan antidote, or N-dichloroacetyl-cis/trans-decahydroquinoline, which islikewise known as an antidote.

The formula (I) provides a general definition of the N-acyl-piperidoneketals according to the invention. Preferably, in this formula,

R¹ represents straight-chain or branched alkyl with 1 to 4 carbon atoms,chlorine or bromine,

R² represents chlorine or bromine,

R³ represents straight-chain or branched alkyl with 1 to 4 carbon atoms,

R⁴ represents straight-chain or branched alkyl with 1 to 4 carbon atoms,or

R³ and R⁴ together represent an alkylene chain which has 2 or 3 carbonatoms and is optionally substituted by methyl and/or ethyl, and

R⁵, R⁶, R⁷ and R⁸ independently of one another represent hydrogen,methyl or ethyl.

If 4-glycolketal-piperidone and α-chloropropionic acid chloride are usedas starting substances, the course of process variant (a) according tothe invention can be represented by the following equation: ##STR6##

If N-dichloroacetyl-4-piperidone and methanol are used as startingsubstances, the course of process variant (b) according to the inventioncan be represented by the following equation: ##STR7##

The formula (II) provides a general definition of the piperidone ketalsrequired as starting substances in process variant (a). In this formula,R³, R⁴, R⁵, R⁶, R⁷ and R⁸ preferably have those meanings which havealready been mentioned as preferred in connection with the descriptionof the compounds of the formula (I).

Some of the piperidone ketals of the formula (II) are known (see BelgianPatent Specification No. 660,763 and Experientia 20, 437-438 (1964)).The piperidone ketals of the formula (II) which have not hitherto beendescribed in the literature can be prepared in a simple manner bymethods which are known in principle. Thus, piperidone ketals of theformula (II) are obtained when the corresponding 4-piperidones arereacted with the particular alcohols in the presence of an acidcatalyst, for example hydrogen chloride, at temperatures between 0° C.and 50° C.

The formula (III) provides a general definition of the alkanoylchlorides also required as starting substances in process variant (a).In this formula, R¹ and R² preferably have those meanings which havealready been mentioned as preferred for R¹ and R² in connection with thedescription of the compounds of the formula (I).

The alkanoyl chlorides of the formula (III) are known, or they can beprepared in a simple manner by processes which are known in principle(see DE-OS (German Published Specification) No. 2,218,097).

Process variant (a) is preferably carried out in the presence of adiluent. Diluents which can be used in this process are water and inertorganic solvents. These solvents include, as preferences, ketones, suchas diethyl ketone and methyl isobutyl ketone; nitriles, such aspropionitrile and acetonitrile; ethers, such as tetrahydrofuran ordioxan; aliphatic and aromatic hydrocarbons, such as petroleum ether,benzene, toluene and xylene; halogenated hydrocarbons, such as methylenechloride, carbon tetrachloride, chloroform or chlorobenzene; esters,such as ethyl acetate; and formamides, such as, in particular,dimethylformamide.

Possible acid-binding agents for carrying out process variant (a) areany of the customary acid acceptors. These include, as preferences,alkali metal hydroxides, such as sodium hydroxide and potassiumhydroxide, alkali metal carbonates, such as sodium carbonate, potassiumcarbonate and sodium bicarbonate, and lower tertiary amines, such astriethylamine, dimethylbenzylamine, pyridine, diazabicyclooctane and1,8-diaza-bicyclo[5.4.0]undec-7-ene. However, piperidone ketal of theformula (II) employed in excess can also simultaneously function as theacid-binding agent. In this case, it is not necessary to add anadditional acid-binding agent.

The reaction temperatures can be varied within a substantial range inprocess variant (a). In general, the reaction is carried out between 0°and 100° C., preferably between 10° and 80° C.

In carrying out process variant (a), 1 to 2 moles of alkanoyl chlorideof the formula (III) and, if appropriate, 1 mole of acid-binding agentare preferably employed per mole of piperidone ketal of the formula(II). Isolation of the reaction products is effected by customarymethods. In general, a procedure is followed in which, when the reactionhas ended, the reaction mixture is filtered, the filtrate isconcentrated and, if appropriate, the residue which remains isrecrystallized.

The formula (IV) provides a general definition of the N-acyl-piperidonesrequired as starting substances in process variant (b). In this formula,R¹, R², R⁵, R⁶, R⁷ and R⁸ preferably have those meanings which havealready been mentioned as preferred in connection with the descriptionof the compounds of the formula (I).

The N-acyl-piperidones of the formula (IV) have not hitherto beendescribed in the literature. However, they can be prepared in a simplemanner by processes which are known in principle. Thus,N-acyl-piperidones of the formula (IV) are obtained when piperidones ofthe general formula ##STR8## in which R⁵, R⁶, R⁷ and R⁸ have themeanings indicated above, are reacted with alkanoyl chlorides of thegeneral formula ##STR9## in which R¹ and R² have the meanings indicatedabove,

if appropriate in the presence of a diluent and if appropriate in thepresence of an acid-binding agent.

Possible diluents and acid-binding agents are those solvents and acidacceptor which have already been mentioned in connection with processvariant (a). The reaction temperatures and the other reaction conditionsalso correspond to those of process variant (a). The piperidones of theformula (VI) are known, or they can be prepared by processes which areknown in principle.

The formula (V) provides a general definition of the alcohols alsorequired as starting substances in process variant (b). In this formula,R⁹ preferably represents straight-chain or branched alkyl with 1 to 4carbon atoms or straight-chain or branched ω-hydroxyalkyl with 2 to 7carbon atoms.

Specific examples of alcohols of the formula (V) which may be mentionedare: methanol, ethanol, propanol, ethylene glycol and propane-1,3-diol.

The alcohols of the formula (V) are known.

Catalysts which can be employed in carrying out process variant (b) areany of the compounds customarily used for ketalization reactions. Thesecompounds include, as preferences, acids, such as hydrogen chloride,hydrogen bromide and toluenesulphonic acid.

The ketalization can also be carried out in the presence of awater-binding agent. Trimethylchlorosilane may be mentioned as anexample.

Preferred diluents for carrying out process variant (b) are the alcoholsfunctioning as reactants. However, it is also possible to employ otherinert organic solvents. Preferred solvents in this case are aliphatic oraromatic, optionally halogenated hydrocarbons, for example benzene,toluene, methylene chloride, chloroform or carbon tetrachloride.

The reaction temperatures can be varied within a substantial range incarrying out process variant (b). In general, the reaction is carriedout at temperatures between 0° C. and 200° C., preferably between 20° C.and 150° C.

In carrying out process variant (b), 2 to 3 moles or even a largerexcess of alcohol of the formula (V) and a small amount of catalyst oran excess of water-binding agent are employed per mole ofN-acyl-piperidone of the formula (IV). Isolation of the reactionproducts is effected by customary methods. In general, a procedure isfollowed in which the volatile components are carefully distilled offand, if appropriate, the residue is recrystallized.

As already mentioned, the N-acyl-piperidone ketals of the formula (I)are suitable for protecting crop plants from damage by herbicidallyactive thiolcarbamates and acetanilides without noticeably influencingtheir herbicidal action.

The N-acyl-piperidone ketals of the formula (I) can preferably be usedas antidotes for protecting crop plants from damage by herbicidallyactive thiolcarbamates of the general formula ##STR10## in which R¹⁰represents lower alkyl, benzyl, chlorobenzyl or alkoxybenzyl and

R¹¹ and R¹² independently of one another represent alkyl with 2 to 4carbon atoms or cyclohexyl, or

R¹¹ and R¹², together with the adjacent nitrogen atom, represent afive-membered to seven-membered heterocyclic ring,

and for protecting crop plants from damage by herbicidally activeacetanilides of the general formula ##STR11## in which R represents anoptionally substituted N-containing heterocyclic radical,

X and Y are identical or different and represent alkyl,

Z represents halogen and

n represents 0, 1 or 2,

and herbicidally active acid-addition salts and metal salt complexesthereof, and of the general formula ##STR12## in which R¹³ representsalkyl, halogen, haloalkyl, alkylthio, alkylsulphonyl, aminosulphonyl,cyano or nitro,

R¹⁴ and R¹⁵ are identical or different and represent hydrogen, alkyl,halogen, haloalkyl or optionally substituted phenyl,

R¹⁶ represents alkyl or optionally substituted phenyl and

m represents 0 (zero) or an integer from 1 to 5,

and of the general formula ##STR13## in which A represents oxygen,sulphur or the grouping >NR²²,

R¹⁹ represents hydrogen or alkyl,

R²⁰ represents hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cyclcalkyl,halogen, optionally substituted aryl, optionally substituted aralkyl orthe grouping --OR²³, --SR²³ or --NR²² R²³,

R²² represents hydrogen, alkyl or optionally substituted aryl,

R²³ represents hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkylor optionally substituted aralkyl,

R¹⁷ represents alkyl,

R¹⁸ represents alkyl or halogen,

R²¹ represents halogen and

p represents 0, 1 or 2,

and of the formula ##STR14## and of the formula ##STR15##

Specific examples of thiolcarbamates of the formula (VII) which may bementioned are: S-ethyl N,N-dipropylthiocarbamate, S-ethylN,N-diisobutylthiocarbamate, S-propyl N-butyl-N-ethylthiocarbamate,S-propyl N,N-diisopropylthiocarbamate, S-ethyl N,N-diethylthiocarbamate,S-ethyl N-ethyl-N-cyclohexylthiocarbamate, S-ethylhexahydro-azepine-1-thiocarbamate, S-p-methoxybenzylN,N-diethylthiocarbamate, S-p-chlorobenzyl N,N-diethylthiocarbamate,S-benzyl N,N-diethylthiocarbamate, S-benzylN,N-di-sec.-butylthiocarbamate and S-propylN-ethyl-N-butylthiocarbamate.

The thiolcarbamates of the formula (VII) and their herbicidal activityare already known (see U.S. Pat. Nos. 2,913,327, 3,037,853, 3,185,720,3,198,786 and 3,582,314).

In the formula (VIII), R preferably represents an optionally substitutedradical selected from pyrazol-1-yl, imidazol-1-yl, 1,2,4-triazol-1-yl,1,2,3-triazol-1-yl, 1,3,4-triazol-1-yl, 1,2,3,4-tetrazol-1-yl andpyrrol-1-yl. Preferred substituents are: halogen (especially fluorine,chlorine and bromine) and alkyl with 1 to 4 carbon atoms. X and Y areidentical or different and preferably represent straight-chain orbranched alkyl with 1 to 4 carbon atoms. Z preferably representschlorine or bromine and the index n represents 0, 1 or 2.

Specific examples of acetanilides of the formula (VIII) which may bementioned are:2-methyl-6-ethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,6-diethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,6-diethyl-N-(1,2,4-triazol-1-yl-methyl)-chloroacetanilide,2,6-dimethyl-N-(1,2,4-triazol-1-yl-methyl)-chloroacetanilide,2-methyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,5-dimethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,3-dimethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2-methyl-6-ethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilidehydrochloride, 2,6-diethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilidehydrochloride,2,6-diethyl-N-[(3,5-dimethyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2,6-diethyl-N-[(3-chloro-1,2,4-triazolyl)-methyl]-chloroacetanilide,2-methyl-6-ethyl-N-[(3,5-dimethyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2-tert.-butyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2-methyl-6-ethyl-N-[(3-bromo-5-methyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2-methyl-6-ethyl-N-[(3-chloro-1,2,4-triazolyl)-methyl]-chloroacetanilideand 2,6-diethyl-N-[(4-chloro-pyrazol-1-yl)-methyl]-chloroacetanilide.

Further preferred acetanilides of the formula (VIII) are listed in thepreparative examples.

The acetanilides of the formula (VII) and their herbicidal activity, andherbicidally active acid addition salts and metal salt complexes thereofare already known (see DE-OS (German Published Specification) No.2,648,008 and DE-OS (German Published Specification) No. 2,704,281).

In the formula (IX), R¹³ preferably represents straight-chain orbranched alkyl with 1 to 6 (especially 1 to 4) carbon atoms, halogen(especially fluorine, chlorine or bromine), haloalkyl with up to 3carbon atoms and up to 5 identical or different halogen atoms (preferredhalogens being fluorine or chlorine, and trifluoromethyl being mentionedas an example), alkylthio or alkylsulphonyl with in either case 1 to 4carbon atoms in the alkyl part, aminosulphonyl, cyano or nitro. R¹⁴ andR¹⁵ are identical or different and preferably represent hydrogen,straight-chain or branched alkyl with 1 to 4 carbon atoms, halogen(especially fluorine, chlorine or bromine), haloalkyl with up to 3carbon atoms and up to 5 identical or different halogen atoms (preferredhalogens being fluorine and chlorine) or phenyl which is optionallymono-substituted or polysubstituted, preferred substituents being theradicals mentioned for R¹³. R¹⁶ preferably represents straight-chain orbranched alkyl with 1 to 6 (especially 1 to 4) carbon atoms or phenylwhich is optionally monosubstituted or polysubstituted, preferredsubstituents being: alkyl with 1 to 4 carbon atoms, halogen (especiallyfluorine, chlorine and bromine), haloalkyl with up to 3 carbon atoms andup to 5 identical or different halogen atoms (especially fluorine orchlorine atoms, trifluoromethyl being mentioned as an example), alkoxy,alkylthio or alkylsulphonyl with in each case 1 to 4 carbon atoms,aminosulphonyl, cyano, nitro or phenyl or phenoxy, in either caseoptionally substituted by chlorine. The index m preferably represents 1,2 or 3.

Specific examples of acetanilides of the formula (IX) which may bementioned are: 2,6-dimethyl-N-(benzoyl-methyl)chloroacetanilide,2,6-dimethyl-N-(4-chlorobenzoyl-methyl)chloroacetanilide and2-methyl-6-ethyl-N-(benzoyl-methyl)chloroacetanilide.

Further preferred acetanilides of the formula (IX) are listed in thepreparative examples.

The acetanilides of the formula (IX) and their herbicidal activity arealready known (see DE-OS (German Published Specification) No.2,726,253).

In the formula (X), A preferably represents oxygen, sulphur or thegrouping --NR²², wherein R²² represents hydrogen, straight-chain orbranched alkyl with 1 to 4 carbon atoms or aryl with 6 to 10 carbonatoms (especially phenyl), it being possible for the aryl radical tocarry one or more substituents selected from halogen, alkyl with 1 to 4carbon atoms, alkoxy with 1 or 2 carbon atoms, alkylthio with 1 or 2carbon atoms, cyano, nitro and haloalkyl with up to 2 carbon atoms andup to 5 identical or different halogen atoms (preferred halogens beingfluorine or chlorine). R¹⁹ preferably represents hydrogen or methyl. R²⁰in the formula (X) preferably represents hydrogen, straight-chain orbranched alkyl with 1 to 4 carbon atoms, haloalkyl with up to 3 carbonatoms and up to 5 identical or different halogen atoms (preferredhalogens being fluorine or chlorine, and trifluoromethyl being mentionedas an example), alkenyl or alkynyl with in either case 2 to 4 carbonatoms, cycloalkyl with 5 to 7 carbon atoms or halogen (especiallyfluorine, chlorine or bromine). R²⁰ furthermore preferably representsaryl with 6 to 10 carbon atoms (especially phenyl), it being possiblefor the aryl radical to carry one or more substituents selected fromhalogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 or 2 carbonatoms, alkylthio with 1 or 2 carbon atoms, cyano, nitro and haloalkylwith up to 2 carbon atoms and up to 5 identical or different halogenatoms (preferred halogens being fluorine or chlorine and trifluoromethylbeing mentioned as a specific example of haloalkyl). R²⁰ furthermorepreferably represents aralkyl with 6 to 10 carbon atoms in the aryl partand 1 to 4 carbon atoms in the alkyl part (especially benzyl), it beingpossible for the aralkyl radical to carry, on the aryl part, one or moresubstituents selected from halogen, alkyl with 1 to 4 carbon atoms,alkoxy with 1 or 2 carbon atoms, alkylthio with 1 or 2 carbon atoms,cyano, nitro and haloalkyl with up to 2 carbon atoms and up to 5identical or different halogen atoms (preferred halogens being fluorineor chlorine, and trifluoromethyl being mentioned as a specific exampleof haloalkyl). R²⁰ also preferably represents the grouping --OR²³,--SR²³ or --NR²² R²³, wherein R²² has the preferred meanings which havealready been mentioned above for this radical, and R²³ representshydrogen, straight-chain or branched alkyl with 1 to 4 carbon atoms,haloalkyl with 1 to 3 carbon atoms and up to 5 identical or differenthalogen atoms (preferred halogens being fluorine and chlorine, andtrifluoromethyl being mentioned as an example), alkenyl or alkynyl within either case 2 to 4 carbon atoms, cycloalkyl with 5 to 7 carbon atomsor aralkyl with 6 to 10 carbon atoms in the aryl part and 1 to 4 carbonatoms in the alkyl part (especially benzyl), it being possible for thearalkyl radical to carry, on the aryl part, one or more substituentsselected from halogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 or2 carbon atoms, alkylthio with 1 or 2 carbon atoms, cyano, nitro andhaloalkyl with up to 2 carbon atoms and up to 5 identical or differenthalogen atoms (preferred halogens being fluorine or chlorine, andtrifluoromethyl being mentioned as a specific example of haloalkyl). Inthe formula (X), R¹⁷ preferably represents straight-chain or branchedalkyl with 1 to 4 carbon atoms, R¹⁸ preferably represents straight-chainor branched alkyl with 1 to 4 carbon atoms, fluorine, chlorine orbromine, and R²¹ preferably represents chlorine, bromine or iodine. Theindex p represents 0, 1 or 2.

Specific examples of acetanilides of the formula (X) which may bementioned are:2,6-diethyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide,2,6-dimethyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide,2-ethyl-6-methyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilideand2-tert.butyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide.

Further preferred acetanilides of the formula (X) are listed in thepreparative examples.

The acetanilides of the formula (X) and their herbicidal activity havenot hitherto been disclosed in the literature. They can be prepared in asimple manner. Thus, acetanilides of the formula (X) are obtained byreacting N-azolylalkylanilines of the general formula ##STR16## in whichR¹⁷, R¹⁸, R¹⁹, R²⁰, A and p have the meanings indicated above,

with haloacetic acid chlorides or anhydrides of the general formula

    R.sup.21 --CH.sub.2 --CO--Cl                               (XIVa)

or

    (R.sup.21 --CH.sub.2 --CO).sub.2 O                         (XIVb),

in which

R²¹ has the meaning indicated above,

in the presence of a diluent and if appropriate in the presence of anacid-binding agent.

If2,6-diethyl-N-(3-methylthio-4-methyl-1,2,4-triazol-5-yl-methyl)-anilineand chloroacetyl chloride are used as starting substances, the course ofthe reaction in the process for the preparation of the acetanilides ofthe formula (X) can be represented by the following equation: ##STR17##

The formula (XIII) provides a general definition of theN-azolylalkylanilines required as starting substances in carrying outthe process for the preparation of the acetanilides of the formula (X).In the formula (XIII), R¹⁷, R¹⁸, R¹⁹, R²⁰, A and p preferably have thosemeanings which have already been mentioned as preferred in connectionwith the description of the acetanilides of the formula (X).

The N-azolylalkylanilines of the formula (XIII) required as startingsubstances in the process for the preparation of the acetanilides (X)have not hitherto been disclosed in the literature. However, they can beprepared in a simple manner by several processes. Thus,N-azolylalkylanilines of the formula (XIII) are obtained by

(A) reacting anilines of the general formula ##STR18## in which R¹⁷, R¹⁸and p have the meanings indicated above,

with azole derivatives of the general formula ##STR19## in which A, R¹⁹and R²⁰ have the meanings indicated above and

Hal' represents chlorine or bromine,

in the presence of an acid-binding agent, for example potassiumcarbonate or sodium carbonate, and in the presence of an inert organicsolvent, for example dimethylformamide or toluene, at temperaturesbetween 20° and 160° C., an excess of aniline of the formula (XV)preferably being employed (see also the preparative Examples), or

(B) reacting hydrazine derivatives of the general formula ##STR20## inwhich R¹⁷, R¹⁸, R¹⁹ and p have the meanings indicated above,

with isocyanates or isothiocyanates of the general formula

    R.sup.22 --N═C═B                                   (XVIII),

in which

B represents oxygen or sulphur and

R²² has the meaning indicated above,

in the presence of an organic solvent, for example an alcohol, ether orhydrocarbon, at temperatures between 0° and 80° C., cyclizing thecompounds formed, of the general formula ##STR21## in which B, R¹⁷, R¹⁸,R¹⁹, R²² and p have the meanings indicated above,

at temperatures between 20° and 100° C. in the presence of a strongbase, for example sodium hydroxide solution or potassium hydroxidesolution, and in the presence of a solvent, for example ethanol orwater, and reacting the triazolones or triazolethiones formed, of thegeneral formula ##STR22## in which B, R¹⁷, R¹⁸, R¹⁹, R²² and p have themeanings indicated above,

with halides of the general formula

    Hal'--R.sup.24                                             (XXI),

in which

Hal' represents chlorine or bromine and

R²⁴ represents the radicals of the substituent R²³, with the exceptionof hydrogen,

in the presence of a strong base, for example sodium hydroxide solution,and in the presence of an inert organic solvent, for example toluene ormethylene chloride, at temperatures between 20° and 80° C., it alsobeing possible to carry out the reaction under phase transfer catalysisand using other alkylating reagents, for example dimethyl sulphate (seealso the preparative examples), or

(C) reacting hydrazine derivatives of the general formula (XVII) withformic acid or acid chlorides or acid anhydrides of the general formula

    R.sup.25 --CO--Cl                                          (XXIIa)

or

    (R.sup.25 --CO--).sub.2 O                                  (XXIIb),

in which

R²⁵ represents alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl,optionally substituted aryl or optionally substituted aralkyl,

in the presence of an inert organic solvent, such as an ether,hydrocarbon or halogenated hydrocarbon, at temperatures between 0° and50° C. and either cyclizing the compounds formed, of the general formula##STR23## in which R¹⁷, R¹⁸, R¹⁹, R²⁵ and p have the meanings indicatedabove,

with diphosphorus pentasulphide in a manner which is in itself known(see Chem. Ber. 32, 797 (1899) and J. prakt. Chemie 69, 145 (1904)) togive thiadiazole derivatives, or reacting them with customarydehydrating reagents, also in a known manner, to give oxadiazolederivatives (see, in this context, Elderfield, Heterocyclic Compounds,Volume 7 (1961)) or

(D) reacting hydrazine derivatives of the general formula (XVII) withnitriles of the general formula

    R.sup.26 --C.tbd.N                                         (XXIV),

in which

R²⁶ represents alkyl, haloalkyl or optionally substituted aryl,

in a manner which is in itself known, to give triazole derivatives (seeChem. Ber. 96, 1064 (1963)), or (E) reacting hydrazine derivatives ofthe general formula (XVII) with imino-ethers of the general formula##STR24## in which R²⁵ represents alkyl, haloalkyl, alkenyl, alkynyl,cycloalkyl, optionally substituted aryl or optionally substitutedaralkyl and

R²⁷ represents methyl or ethyl,

in a manner which is in itself known, under reflux and in the presenceof an inert organic solvent, for example ethanol, to give oxadiazolederivatives, or

(F) reacting the anilines of the formula (XV) with azolealdehydes of thegeneral formula ##STR25## in which R²² has the meaning indicated above,in the presence of an inert organic solvent, for example toluene, attemperatures between 80° and 120° C., and reducing the compounds formed,of the general formula ##STR26## in which A, R¹⁷, R¹⁸, R²⁰ and p havethe meanings indicated above,

in a generally known manner, for example by reaction with a complexhydride, such as sodium borohydride, if appropriate in the presence of apolar organic solvent, such as methanol, at temperatures between 0° and80° C.

The compounds of the formulae (XV) and (XVI) required as startingsubstances in process (A) are known, or they can be prepared byprocesses which are known in principle (see Helv. Chim. Acta 55, 199 etseq. (1972), Chem. Ber. 32, 797 et seq. (1899) and Chem. Ber. 96, 1049et seq. (1963)).

The starting substances of the formula (XVII) required in process (B)have not hitherto been disclosed in the literature. However, they can beprepared by known processes, by reacting known esters (see, inter alia,DT-OS's (German Published Spcifications) Nos. 2,350,944 and 2,513,730)of the general formula ##STR27## in which R¹⁷, R¹⁸, R¹⁹ and p have themeanings indicated above and

R²⁷ represents methyl or ethyl,

with hydrazine hydrate, preferably in the presence of an organicsolvent, for example ethanol, dioxan or dimethylformamide, attemperatures between 20° and 120° C. (see also the preparativeexamples).

The reaction components of the formulae (XVIII) and (XXI) required inprocess (B) are generally known compounds of organic chemistry.

The substances of the formulae (XXIIa), (XXIIb), (XXIV) and (XXV)required as reaction components in processes (C), (D) and (E) arelikewise known.

The azole-aldehyde of the formula (XXVI) to be used as reactioncomponents in process (F) are also known, or they can be prepared byprocesses which are known in principle (see Elderfield, "HeterocyclicCompounds", Volume 7 (1961) and "Advances in Heterocyclic Chemistry",Volume 9 (1968)).

The formulae (XIVa) and (XIVb) provide general definitions of thehaloacetic acid chlorides and anhydrides also required as startingsubstances in the preparation of the acetanilides of the formula (X). Inthe formulae (XIVa) and (XIVb), R²¹ preferably represents chlorine,bromine or iodine.

The haloacetic acid chlorides and anhydrides of the formulae (XIVa) and(XIVb) are generally known compounds of organic chemistry.

Preferred diluents for the reaction for the preparation of theacetanilides of the formula (X) are inert organic solvents. Theseinclude, as preferences, ketones, such as diethyl ketone, and inparticular acetone and methyl ethyl ketone; nitriles, such aspropionitrile, and in particular acetonitrile; ethers, such astetrahydrofuran or dioxane; aliphatic and aromatic hydrocarbons, such aspetroleum ether, benzene, toluene or xylene; halogenated hydrocarbons,such as methylene chloride, carbon tetrachloride, chloroform andchlorobenzene; and esters, such as ethyl acetate.

If appropriate, the process for the preparation of acetanilides of theformula (X) can be carried out in the presence of acid-binding agents(hydrogen chloride acceptors). Any of the customary acid-binding agentscan be used in this process. These agents include, as preferences,organic bases, such as tertiary amines, for example triethylamine, orsuch as pyridine; and furthermore inorganic bases, for example alkalimetal hydroxides and alkali metal carbonates.

The reaction temperatures can be varied within a substantial range incarrying out the process for the preparation of the acetanilides of theformula (X). In general, the reaction is carried out at temperaturesbetween 0° C. and 120° C., preferably between 20° C. and 100° C.

1.5 moles of haloacetylating agent and 1 to 1.5 moles of acid-bindingagent are generally employed in carrying out the process for thepreparation of the acetanilides of the formula (X). Isolation of thecompounds of the formula (X) is effected in the customary manner.

Further preferred acetanilides with which the compounds of the formula(I) according to the invention can be employed as antidotes are thecompounds of the formulae (XI) and (XII). These substances and theirherbicidal activity are already known (see U.S. Pat. No. 3,442,945 andDE-OS (German Published Specification) No. 2,328,340).

The N-acyl-piperidone ketals of the formula (I) according to theinvention are particularly suitable for protecting important cropplants, such as maize, soya bean, cotton, sugar beet, cereals, rice andcane sugar, from herbicidal damage by thiolcarbamates and acetanilides.

The active compound combinations according to the invention, whichcomprise an N-acyl-piperidone ketal of the formula (I) and at least oneherbicidally active thiolcarbamate and/or at least one herbicidallyactive acetanilide, exhibit a very good action against broad-leavedweeds and graminaceous weeds in numerous crops of useful plants. Theycan therefore be used for selectively combating weeds in numerous cropsof useful plants. By weeds, in the broadest sense, there are to beunderstood in this context all plants which grow in locations where byare undesired.

The active compound combinations according to the present invention maybe used, for example, to combat the following plants:

dicotyledon weeds of the genera Sinapis, Lepidium, Galium, Stellaria,Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum,Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Rorippa, Rotala,Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis,Papaver, Centaurea and Solanum; and

monocotyledon weeds of the genera Echinochloa, setaria, Panicum,Digitaria, Phelum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochloria, Fimbristylis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus and Apera.

The active compound combinations according to the present invention maybe used, for example, as selective herbicides in the following cultures:

dicotyledon cultures of the genera Gossypium, Glycine, Beta, Daucus,Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana,Lycopersicon, Arachis, Brassica, Lactuca, Cucumis and Cucurbita; and

monocotyledon cultures of the genera Oryza, Zea, Triticum, Hordeum,Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus andAllium.

The active compound combinations according to the invention areparticularly suitable for selectively combating weeds in maize, soyabean, cotton, sugar beet, cerals, rice and cane sugar.

The antidotes according to the invention can be converted, ifappropriate as a mixture with the herbicidal active compounds with whichthey are employed, into the customary formulations, such as solutions,emulsions, wettable powders, suspensions, powders, dusting agents,foams, pastes, soluble powders, granules, suspension-emulsionconcentrates, natural and synthetic materials impregnated with activecompound, very fine capsules in polymeric substances and in coatingcompositions, for use on seed.

These formulations are produced in known manner, for example by mixingthe antidotes according to the invention, if appropriate as a mixturewith the herbicidal active compounds with which they are employed, withextenders, that is to say liquid or solid diluents or carriers,optionally with the use of surface-active agents, that is to sayemulsifying agents and/or dispersing agents and/or foam-forming agents.In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents.

As liquid diluents or carriers, especially solvents, there are suitablein the main, aromatic hydrocarbons, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatic or chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic or alicyclic hydrocarbons, such as cyclohexane orparaffins, for example mineral oil fractions, alcohols, such as butanolor glycol as well as their ethers and esters, ketones, such as acetone,methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, orstrongly polar solvents, such as dimethylformamide anddimethylsulphoxide, as well as water.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, maize cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

Adhesive such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulations.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalocyaninedyestuffs, and trace nutrients, such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95% by weight ofantidote or antidote and herbicidal active compound, preferably between0.5 and 90%.

The antidotes according to the invention, as such or in the form oftheir formulations, can, as stated above, also be employed as mixtureswith herbicidal active compounds, finished formulations or tank mixingbeing possible. Mixtures with other active compounds, such as fungicidesinsecticides, acaricides, nematicides, bird repellants, growth factors,plant nutrients and agents which improve soil structure are alsopossible.

The antidotes according to the invention or mixtures of the antidotesaccording to the invention and a herbicidal active compound can beemployed as such, in the form of their formulations or in the use formsprepared therefrom by further dilution, such as ready-to-use solutions,suspensions, emulsions, powders and granules. They may be used in thecustomary manner, for example by watering, spraying, atomizing, dustingor scattering, dry dressing, moist dressing, wet dressing, slurrydressing or encrusting.

The antidotes according to the invention can be applied by methodscustomary for antidotes of this type. Thus, the antidotes according tothe invention can be applied either before or after the herbicide, orcan be applied together with the herbicide. If the herbicide is usedbefore or after sowing, crop plants can also be protected from damage bytreating the seed with the antidotes before sowing (dressing). A furtherpossible way of using the antidotes is to apply them to the seed furrowduring sowing. If the plants are seedlings, these can be treated withthe antidotes before being transplanted.

When the antidotes according to the invention are employed, thecustomary amounts, at the location, of the particular herbicides areapplied. The amounts of herbicidal active compound used vary between 0.5and 5 kg/ha. The amount of antidote used is independent of the herbicideand of the amount of herbicidal active compound used. In general, theamounts of antidotes according to the invention applied are between 0.1and 5 kg/ha in the case of treatment of the soil surface, preferablybetween 0.2 and 4 kg/ha. In the case of seed treatment, the amounts ofantidotes according to the invention applied are in general between 10and 300 g per kilogram of seed, preferably between 25 and 200 g perkilogram of seed.

The weight ratios of antidotes to herbicidal active compounds in theactive compound combinations according to the invention can vary withinrelatively wide limits. In general, 0.04 to 1.0 part by weight,preferably 0.1 to 0.5 part by weight, of antidote of the formula (I) ispresent per 1 part by weight of herbicidal active compound.

Thus, the present invention also provides an antidote compositioncontaining as active ingredient a compound of the formula (I) inadmixture with a solid diluent or carrier or in admixture with a liquiddiluent or carrier containing a surface-active agent.

The present invention also provides a method of protecting crop plantsfrom damage by herbicidally active thiolcarbamates or herbicidallyactive acetanilides, in which there is applied to the plants, or to ahabitat thereof, a compound of the formula (I) alone or in the form of acomposition containing as active ingredient a compound of the formula(I) in admixture with a diluent or carrier.

The present invention also provides crops protected from damage byherbicidally active thiolcarbamates or by herbicidally activeacetanilides by being grown in areas in which immediately prior toand/or during the time of the growing a compound of the formula (I) wasapplied, alone or in admixture with a diluent or carrier.

The present invention also provides a herbicidal composition thatcontains as active ingredients (1) a compound of the formula (I) and (2)at least one herbicidally active compound selected from thiolcarbamatesand acetanilides, alone or in admixture with a solid or liquid diluentor carrier.

The present invention also provides a method of combating weeds, inwhich there is applied to the weeds, or to a habitat thereof, aherbicidal composition according to the present invention.

The present invention further provides crops protected from damage byweeds by being grown in areas in which immediately prior to and/orduring the time of the growing, a herbicidal composition of the presentinvention was applied.

It will be seen that the usual methods of providing a harvested crop maybe improved by the present invention.

The good activity of the antidotes according to the invention can beseen from the example which follows.

In this example, the compounds indicated below are employed ascomparison compounds: ##STR28##

Furthermore, the acetanilide indicated below is employed as theherbicidal active compound in this example: ##STR29##

EXAMPLE A Pre-emergence Test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof herbicidal active compound or antidote, or or a mixture of antidoteand herbicidal active compound, was mixed with the stated amount ofsolvent, the stated amount of emulsifier was added and the concentratewas diluted with water to the desired concentration.

Seeds of the test plants were sown in normal soil and, after 24 hours,watered with the herbicide preparation or antidote preparation or withthe preparation of antidote and herbicidal active compound. It wasexpedient to keep constant the amount of water per unit area. Theconcentration of the active compound in the preparation was of noimportance, only the amount of active compound applied per unit areabeing decisive. After three weeks, the degree of damage to the plantswas rated in % damage in comparison to the development of the untreatedcontrol. The figures denotes:

0%=no action (like untreated control)

100%=total destruction

Evaluation of the test results showed that the compound (1) (seepreparative Example 1) was more suitable for protecting crop plants fromdamage by the compound (C) than the comparison compounds (A) and (B).

PREPARATIVE EXAMPLES Example 1 ##STR30##

12.4 g (0.084 mol) of dichloroacetyl chloride were added dropwise to amixture of 12 g (0.084 mol) of piperid-4-one ethylene ketal and 12.8 g(0.084 mol) of 1,8-diazabicyclo[5.4.0]undec-7-ene in 100 ml of toluene,whilst stirring, at a rate such that the temperature of the reactionmixture did not exceed 40° C. Thereafter, the mixture was subsequentlystirred at 20° C. for 2 hours. Working up was then effected by aprocedure in which the reaction mixture was filtered, the filtrate wasconcentrated under reduced pressure and the residue was recrystallizedfrom a mixture of toluene and petroleum ether. 10.5 g (49% of theory) ofN-dichloroacetyl-piperid-4-one ethylene ketal were obtained in thismanner in the form of colorless crystals of melting point 102° C.

Example 2 ##STR31##

A mixture of 19 g (0.09 mol) of N-dichloroacetyl-piperid-4-one, 7.5 g(0.099 mol) of propane-1,3-diol and 22.4 g (0.21 mol) oftrimethylchlorosilane was boiled under reflux for 12 hours, whilestirring. Thereafter, the reaction mixture was concentrated underreduced pressure and the residue was then subjected to brief incipientdistillation under gravity reduced pressure. The resulting brown oil,which slowly crystallized completely, was recrystallized from 200 ml oftoluene. 16 g (66.6% of theory) of N-dichloroacetyl-piperid-4-onepropylene ketal of melting point 115° C. were obtained.

    ______________________________________                                        Analysis:   C       H          Cl    N                                        ______________________________________                                        calculated: 44.7%   5.5%       26.4% 5.2%                                     found:      44.5%   5.6%       26.0% 5.7%                                     ______________________________________                                    

The N-acyl-piperidone ketals of the formula (I) listed in Table 1 belowwere also prepared by the methods analogous to those described inExamples 1 and 2.

                  TABLE 1                                                         ______________________________________                                         ##STR32##                     (I)                                                                                             Refrac-                                                                       tive in-                     Ex-                                              dex or                       am-                                              melting                      ple                                              point                        No.  R.sup.1                                                                              R.sup.2                                                                             R.sup.3 R.sup.4                                                                              R.sup.5                                                                           R.sup.6                                                                           R.sup.7                                                                           R.sup.8                                                                           [°C.]                 ______________________________________                                        3    Cl     Cl    CH.sub.3                                                                              CH.sub.3                                                                             H   H   H   H   76                           4    Cl     Cl    C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                      H   H   H   H   64                           5    CH.sub.3                                                                             Cl    CH.sub.2CH.sub.2                                                                           H   H   H   H   n .sub.D.sup.23 =                                                             1.5059                         6    CH.sub.3                                                                             Cl    CH .sub.2CH.sub.2CH .sub.2                                                                 H   H   H   H   70                             7    CH.sub.3                                                                             Cl    C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                      H   H   H   H   n .sub.D.sup.23 =                                                             1.5091                       ______________________________________                                         Example (VIII-1)     ##STR33##

A mixture of 68 g (1 mol) of pyrazole and 106 g (1.05 mol) oftriethylamine in 150 ml of anhydrous ethyl acetate was added to 274.2 g(1 mol) of 2,6-diethyl-N-chloromethyl-chloroacetanilide in 250 ml ofanhydrous ethyl acetate, while stirring, whereupon the temperature roseto 30° C. The mixture was subsequently stirred at room temperature for 1hour. There were two possibilities for the working up:

(1) The reaction mixture was filtered and the filtrate was washed withwater until neutral, dried over sodium sulphate and evaporated in vacuo.After fractional crystallization of the residue with ligroin, 171.2 g(56% of theory) of 2,6-diethyl-N-(pyrazol-1-yl-methyl)chloroacetanilideof melting point 67° C. were obtained in the form of colorless crystals.

(2) The reaction mixture was cooled to 0° C. and filtered and theresidue on the filter was rinsed with 10 ml of cold ethyl acetate. 50 g(1.4 mol) of dry hydrogen chloride were passed into the filtrate at 0°to -10° C. The hydrochloride salts which has precipitated were thenfiltered off and rinsed with 50 ml of cold ethyl acetate and the solidresidue was subsequently partitioned between 0.5 liter of ethyl acetateand 0.5 liter of aqueous sodium hydroxide solution with a pH value of12. The organic phase was separated off, washed twice with 0.5 liter ofsodium chloride solution each time, dried over sodium sulphate andevaporated in vacuo. 60 ml of benzine were added to the colorless oilyresidue, whereupon the residue crystallized. 220.2 g (72% of theory of2,6-diethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide of melting point67° C. were obtained in the form of colorless crystals.

The compounds listed in the table below are prepared in an analogousmanner:

                  TABLE 2                                                         ______________________________________                                         ##STR34##                   (VIII)                                                                                   Melting                               Example                                 point                                 No.    X        Y.sub.n   Z   R         (°C.)                          ______________________________________                                        VIII-2 C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  1,2,4-Tria-                                                                             112                                                                 zol-1-yl                                        VIII-3 i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  Pyrazol-1-yl                                                                            134                                   VIII-4 CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  1,2,4-Tria-                                                                             92                                                                  zol-1-yl                                        VIII-5 CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  Pyrazol-1-yl                                                                            57                                    VIII-6 C.sub.2 H.sub.5                                                                        4,6-(CH.sub.3).sub.2                                                                    Cl  Pyrazol-1-yl                                                                            32                                    VIII-7 CH.sub.3 4,6-(CH.sub.3).sub.2                                                                    Cl  Pyrazol-1-yl                                                                            92                                    VIII-8 C.sub.2 H.sub.5                                                                        4-CH.sub.3,                                                                             Cl  Pyrazol-1-yl                                                                            78                                                    6-C.sub.2 H.sub.5                                             VIII-9 i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  1,3,4-Tria-                                                                             196                                                                 zol-1-yl                                        VIII-10                                                                              i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  1,2,4-Tria-                                                                             138                                                                 zol-1-yl                                        VIII-11                                                                              C.sub.2 H.sub.5                                                                        6-C.sub. 2 H.sub.5                                                                      Cl  Pyrrol-1-yl                                                                             oil                                   VIII-12                                                                              i-C.sub.3 H.sub.7                                                                      --        Cl  1,2,4-Tria-                                                                             118                                                                 zol-1-yl                                        VIII-13                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  1,2,3,4,-Tetra-                                                                         oil                                                                 zol-1-yl                                        VIII-14                                                                              i-C.sub.3 H.sub.7                                                                      --        Cl  Pyrazol-1-yl                                                                            oil                                   VIII-15                                                                              C.sub.2 H.sub.5                                                                        --        Cl  1,2,4-Tria-                                                                             81                                                                  zol-1-yl                                        VIII-16                                                                              CH.sub.3 6-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                                                            82                                    VIII-17                                                                              CH.sub.3 6-CH.sub.3                                                                              Cl  1,2,4-Tria-                                                                             110                                                                 zol-1-yl                                        VIII-18                                                                              CH.sub.3 5-CH.sub.3                                                                              Cl  1,2,4-Tria-                                                                             oil                                                                 zol-1-yl                                        VIII-19                                                                              CH.sub.3 --        Cl  Pyrazol-1-yl                                                                            56                                    VIII-20                                                                              CH.sub.3 --        Cl  1,2,4-Tria-                                                                             88                                                                  zol-1-yl                                        VIII-21                                                                              CH.sub.3 5-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                                                            oil                                   VIII-22                                                                              CH.sub.3 3-CH.sub.3                                                                              Cl  1,2,4-Tria-                                                                             114                                                                 zol-1-yl                                        VIII-23                                                                              CH.sub.3 3-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                                                            102                                   VIII-24                                                                              C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                                                            87                                                                  (×HCl)                                    VIII-25                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Pyrazol-1-yl                                                                            67                                                                  (×HCl)                                    VIII-26                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3,5-Dimethyl-                                                                           111                                                                 pyrazol-1-yl                                    VIII-27                                                                              C.sub.2 H.sub. 5                                                                       6-C.sub.2 H.sub.5                                                                       Cl  Bromo-methyl-                                                                           145                                                                 pyrazolyl                                       VIII-28                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3-Chloro-1,2,4-                                                                         110                                                                 triazol-1-yl                                    VIII-29                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  3,5-Dimethyl-                                                                           90                                                                  pyrazol-1-yl                                    VIII-30                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3-Methyl- 89                                                                  pyrazol-1-yl                                    VIII-31                                                                              C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  3-Methyl- 113                                                                 pyrazol-1-yl                                    VIII-32                                                                              C(CH.sub.3).sub.3                                                                      --        Cl  Pyrazol-1-yl                                                                            oil                                   VIII-33                                                                              C(CH.sub.3).sub.3                                                                      --        Cl  1,2,4-Tria-                                                                             118                                                                 zol-1-yl                                        VIII-34                                                                              C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  Bromo-methyl-                                                                           80                                                                  pyrazolyl                                       VIII-35                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  4-Chloro-pyra-                                                                          91                                                                  zol-1-yl                                        VIII-36                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  3-Chloro-1,2,4-                                                                         121                                                                 triazol-1-yl                                    VIII-37                                                                              C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  2,4,5-Trichloro-                                                                        158                                                                 imidazol-1-yl                                   VIII-38                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  4-Chloro- 110                                                                 pyrazol-1-yl                                    VIII-39                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  1,2,3,4-Tetrazol-                                                                       110                                                                 1-yl                                            VIII-40                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub. 5                                                                      Br  Pyrazol-1-yl                                                                            68                                    VIII-41                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Br  Pyrazol-1-yl                                                                            67                                    VIII-42                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Imidazol-1-yl                                                                           oil                                   VIII-43                                                                              C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Br  1,2,4-Tria-                                                                             90                                                                  zol-1-yl                                        VIII-44                                                                              CH.sub.3 6-C.sub.2 H.sub.5                                                                       Br  1,2,4-Tria-                                                                             78                                                                  zol-1-yl                                        ______________________________________                                    

Example (IX-1) ##STR35##

16 ml (0.2 mol) of chloroacetyl chloride were added dropwise to asolution of 18.5 g (0.068 mol) of2,6-dimethyl-N-(4-chloro-benzylmethyl)-aniline in 150 ml of benzene.Thereafter, the mixture was stirred under reflux for 15 hours and wasconcentrated by distilling off the solvent and the excess chloroacetylchloride in vacuo. The residue was triturated with a mixture ofether/petroleum ether (1:3) and the crystalline residue formed wasfiltered off and dried. 17.7 g (75.5% of theory of2,6-dimethyl-N-(4-chlorobenzoyl-methyl)-chloroacetanilide of meltingpoint 128° C. were obtained.

Example (IX-2) ##STR36##

23.3 g (0.1 mol) of 2-ethyl-6-methyl-N-pivaloyl-methylaniline weredissolved in 100 ml of benzene, and 24 ml (0.3 mol) of chloroacetylchloride were added. Thereafter, the mixture was stirred under refluxfor 15 hours and was concentrated by distilling off the solvent and theexcess chloroacetyl chloride in vacuo. The oily residue was stirred withpetroleum ether, the mixture was decanted the product phase was stirredwith active charcoal and filtered and the filtrate was concentrated invacuo. The residue was stirred with n-hexane and the resulting solid isfiltered off and dried. 13.7 g (45% of theory) of2-ethyl-6-methyl-N-pivaloylmethyl-chloroacetanilide of melting point 86°C. were obtained.

The compounds listed in Table 3 below were also prepared by the methodsdescribed in Examples (IX-1) and (IX-2)

The compounds listed thereafter in Table 4 below could also be obtainedin an analogous manner.

                                      TABLE 3                                     __________________________________________________________________________     ##STR37##                            (IX)                                    Example                        Melting point (°C.)                     No.  R.sup.13.sub.m                                                                          R.sup.14                                                                         R.sup.15                                                                           R.sup.16                                                                              or refractive index                            __________________________________________________________________________    IX-3 2-CH.sub.3                                                                              H  H                                                                                   ##STR38##                                                                            138                                            IX-4 2-CH.sub.3                                                                              H  H                                                                                   ##STR39##                                                                            140                                            IX-5 2,6-(C.sub.2 H.sub.5).sub.2                                                             H  H                                                                                   ##STR40##                                                                            134                                            IX-6 2,6-(C.sub.2 H.sub.5).sub.2                                                             H  H                                                                                   ##STR41##                                                                            116                                            IX-7 2-Cl      H  H                                                                                   ##STR42##                                                                            124                                            IX-8 2,6-(CH.sub.3).sub.2                                                                    H  H                                                                                   ##STR43##                                                                            100                                            IX-9 4-Cl      H  H                                                                                   ##STR44##                                                                            114                                            IX-10                                                                              2,6-(CH.sub.3).sub.2                                                                    CH.sub.3                                                                         H    CH.sub.3                                                                              104                                            IX-11                                                                              2,6-(i-C.sub.3 H.sub.7).sub.2                                                           H  H                                                                                   ##STR45##                                                                            200                                            IX-12                                                                              2,6-(X.sub.2 H.sub.5).sub.2, 4-CH.sub.3                                                 H  H                                                                                   ##STR46##                                                                            112                                            IX-13                                                                              2,6-(i-C.sub.3 H.sub.7).sub.2                                                           H  H                                                                                   ##STR47##                                                                            140                                            IX-14                                                                              2,6-(CH.sub.3).sub.2                                                                    H  H                                                                                   ##STR48##                                                                             90                                            IX-15                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                           H  H                                                                                   ##STR49##                                                                             70                                            IX-16                                                                              2,6-(CH.sub.2).sub.2                                                                    H  H                                                                                   ##STR50##                                                                            114                                            IX-17                                                                              2-C.sub.2 H.sub.5, 4,6-(CH.sub.3).sub.2                                                 H  H                                                                                   ##STR51##                                                                            n.sub.D.sup.20 = 1.5680                        IX-18                                                                              2,6-(CH.sub.3).sub.2                                                                    H  H                                                                                   ##STR52##                                                                            104                                            IX-19                                                                              2,4,6-(CH.sub.3).sub.3                                                                  H  H                                                                                   ##STR53##                                                                            134                                            IX-20                                                                              2,4,6-(CH.sub.3).sub.3                                                                  H  H                                                                                   ##STR54##                                                                            n.sub.D.sup.20 = 1.5610                        IX-21                                                                              2,6-(CH.sub.3).sub.2                                                                    H                                                                                 ##STR55##                                                                          ##STR56##                                                                            149                                            IX-22                                                                              2,6-(CH.sub.3).sub.2                                                                    H  CH.sub.3                                                                            ##STR57##                                                                             84                                            __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________     ##STR58##                         (IX)                                       Example                                                                       No.  R.sup.13.sub.m                                                                           R.sup.14                                                                         R.sup.15                                                                              R.sup.16                                           __________________________________________________________________________    IX-23                                                                              3,5-(CF.sub.3).sub.2                                                                     H  H                                                                                      ##STR59##                                         IX-24                                                                              2,6-(CH.sub.3).sub.2                                                                     H  H                                                                                      ##STR60##                                         IX-25                                                                              2,6-(CH.sub.3).sub.2                                                                     H  H                                                                                      ##STR61##                                         IX-26                                                                              2,6-(CH.sub.3).sub.2                                                                     H  H                                                                                      ##STR62##                                         IX-27                                                                              2,6-(CH.sub.3).sub.2, 4-SO.sub.2 NH.sub.2                                                H  H                                                                                      ##STR63##                                         IX-28                                                                              2-Cl, 6-CH.sub.3                                                                         H  H                                                                                      ##STR64##                                         IX-29                                                                              2-C.sub. 2 H.sub.5, 6-CH.sub.3                                                           CH.sub.3                                                                         CH.sub.3                                                                               ##STR65##                                         IX-30                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            CH.sub.3                                                                         CH.sub.3                                                                               ##STR66##                                         IX-31                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            CH.sub.3                                                                         CH.sub.3                                                                               ##STR67##                                         IX-32                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            CH.sub.3                                                                         CH.sub.3                                                                               ##STR68##                                         IX-33                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            CH.sub.3                                                                         CH.sub.3                                                                               ##STR69##                                         IX-34                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            H  CH.sub.3                                                                               ##STR70##                                         IX-35                                                                              2-C.sub.2 H.sub.5, 6-CH.sub.3                                                            H  CH.sub.3                                                                               ##STR71##                                         IX-36                                                                              2,6-(CH.sub.3).sub.2                                                                     H                                                                                 ##STR72##                                                                             ##STR73##                                         IX-37                                                                              2,6-(CH.sub.3).sub.2                                                                     H                                                                                 ##STR74##                                                                             ##STR75##                                         IX-38                                                                              2,6-(CH.sub.3).sub.2                                                                     H                                                                                 ##STR76##                                                                             ##STR77##                                         IX-39                                                                              2,6-(CH.sub.3).sub.2                                                                     H                                                                                 ##STR78##                                                                             ##STR79##                                         IX-40                                                                              2,6-(CH.sub.3).sub.2                                                                     H                                                                                 ##STR80##                                                                             ##STR81##                                         IX-41                                                                              2,6-(CH.sub.3).sub.2                                                                     H  CH.sub.3                                                                               ##STR82##                                         __________________________________________________________________________

Example (X-1) ##STR83##

16.3 g (0.07 mol) of2-ethyl-6-methyl-N-[(2-methyl-1,3,4-oxadiazol-6-yl)-methyl]-aniline and6 g (0.076 mol) of anhydrous pyridine in 100 ml of absolutetetrahydrofuran were heated to the boiling point, while stirring, and asolution of 8 g (0.07 mol) of chloroacetyl chloride in 20 ml oftetrahydrofuran was added dropwise. When the dropwise addition hadended, the mixture was subsequently stirred for 10 minutes and wasconcentrated by distilling off the solvent and the residue was stirredwith 150 ml of water. The reaction product which crystallized out wasfiltered off, washed with water and dried. 18.7 g (87% of theory) ofbeige- colored crystals of2-ethyl-6-methyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilideof melting point 67° to 70° C. were obtained.

Preparation of the Starting Material ##STR84##

A mixture of 101.2 g (0.76 mol) of 2-ethyl-6-methylaniline, 40 g (0.3mol) of 2-methyl-5-chloromethyl-1,3,5-oxadiazole, 41.4 g (0.3 mol) ofpowdered potassium carbonate and 76 ml of dimethylformamide was heatedto 100° C. under reflux for 5 hours. Thereafter, the reaction mixturewas filtered and the filtrate was diluted with methylene chloride andwashed several times with water. The methylene chloride phase was driedover sodium sulphate and concentrated by distilling off the solvent invacuo. The residue was distilled in vacuo. 46.8 g (67.5% of theory) of ayellowish oil consisting of2-ethyl-6-methyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl)-aniline witha boiling point of 140° to 142° C./0.1 mm and a purity of 94%(determined by gas chromatography) were obtained.

Example (X-2) ##STR85##

5 g (0.017 mol) of2,6-diethyl-N-[(1-methyl-2-methylthio-1,3,4-triazol-5-yl)-methyl]-anilineand 1.6 g (0.02 mol) of pyridine were stirred in 100 ml of absolutetetrahydrofuran, and 2.3 g (0.02 mol) of chloroacetyl chloride wereadded dropwise at room temperature, whereupon the temperature rose toabout 30° C. The mixture was stirred for 2 hours and was partlyconcentrated by distilling off the solvent, and water was added. Theproduct which crystallized out was filtered off, dried andrecrystallized from diisopropyl ether/ethyl acetate. 5 g (80% of theory)of2,6-diethyl-N-[(1-methyl-2-methylthio-1,3,4-triazol-5-yl)-methyl]-chloroacetanilideof melting point 121° to 123° C. were obtained.

Preparation of the Precursors ##STR86##

13.9 g (0.05 mol) of2,6-diethyl-N-[(1-methyl-2-thiono-1,3,4-triazol-5-yl)-methyl]-anilinewere stirred rapidly, at room temperature, in a two-phase mixture of 150ml of toluene and 40 ml of 50% strength sodium hydroxide solution, withthe addition of 1.5 g of triethyl-benzyl-ammonium chloride (TEBA) as acatalyst, and 6.3 g (0.05 mol) of dimethyl sulphate were added dropwise,whereupon the temperature rose to about 25° C. The mixture wassubsequently stirred for 5 hours and the toluene phase was separatedoff, washed several times with water, dried over sodium sulphate andconcentrated by distilling off the solvent. The oil which remained wasmade to crystallize by adding petroleum ether. After recrystallizationfrom petroleum ether, 6.7 g (40% of theory) of b2,6-diethyl-N-[(1-methyl-2-methylthio-1,3,4-triazol-5-yl)-methyl]-anilineof melting point 65° to 67° C. were obtained. ##STR87##

29.6 g (0.1 mol) of1-methyl-4-[(2,6-diethylanilino)-acetyl]-thiosemicarbazide weresuspended in 150 ml of ethanol and, after adding 7 g of potassiumhydroxide in 20 ml of water, the mixture was heated under reflux for 1hour. Thereafter, most of the solvent was distilled off and 250 ml ofwater were added to the residue. After acidifying the mixture to pH 5with glacial acetic acid, the precipitate formed was filtered off andwashed thoroughly with water. After drying, 27 g (97% of theory) of2,6-diethyl-N-[(1-methyl-2-thiono-1,3,4-triazol-5-yl)methyl]-aniline ofmelting point 117° to 121° C. were obtained. ##STR88##

44.2 g (0.2 mol) of 2,6-diethyl-anilino-acetic acid hydrazide and 14.8 g(0.2 mol) of methyl isothiocyanate were dissolved in 250 ml of ethanoland the solution was heated to the reflux temperature for one hour.After subsequently cooling the solution to room temperature, theprecipitate which had formed was filtered off and rinsed twice with 50ml of ethanol each time. After drying, 46 g (78% of theory) of1-methyl-4-[(2,6-diethyl-anilino)-acetyl]-thiosemicarbazide wereobtained in the form of a colourless crystalline substance of meltingpoint 166° C. ##STR89##

58.7 g (0.25 mol) of 2,6-diethyl-anilino-acetic acid ethyl ester and 25g of hydrazine hydrate were left to stand in 200 ml of ethanol for 24hours. Thereafter the mixture was concentrated by distilling off thesolvent and the residue was extracted by stirring with water. Afterdrying the product, 50.5 g (91% of theory) of colourless crystals of2,6-diethyl-anilino-acetic acid hydrazide of melting point 71° to 73° C.were obtained.

Those compounds listed by means of their formulae in Table 5 wereobtained in a corresponding manner.

                                      TABLE 5                                     __________________________________________________________________________     ##STR90##                                                                    Example                                 Melting point                         No.  R.sup.19                                                                         R.sup.20    R.sup.18                                                                           R.sub.p.sup.17                                                                     A      R.sup.21                                                                         (°C.)                          __________________________________________________________________________    X-3  H  CH.sub.3    C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Cl 79-82                                 X-4  H  CH.sub.3    CH.sub.3                                                                           6-CH.sub.3                                                                         O      Cl 91-93                                 X-5  H  CH.sub.3    C(CH.sub.3).sub.3                                                                   --  O      Cl 102-04                                X-6  H  SCH.sub.2CHCH.sub.2                                                                       C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                   ##STR91##                                                                           Cl    67-70° C.                   X-7  H                                                                                 ##STR92##  CH.sub.3                                                                           6-C.sub. 3 H.sub.5                                                                  ##STR93##                                                                           Cl 115-20                                X-8  H  C.sub.2 H.sub.5                                                                           CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Cl 57-59                                 X-9  H  C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Cl 43-47                                  X-10                                                                              H  i-C.sub.3 H.sub.7                                                                         CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Cl viscous oil                            X-11                                                                              H  CH.sub.3    CH.sub.3                                                                           3-CH.sub.3                                                                          ##STR94##                                                                           Cl glass-like solid                       X-12                                                                              H  CH.sub.3    C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Br 80°                             X-13                                                                              H  CH.sub.3    CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Br    92-94° C.                    X-14                                                                              H  CH.sub.3    i-C.sub.3 H.sub.7                                                                  6-i-C.sub.3 H.sub.7                                                                O      Cl 135-37°                        __________________________________________________________________________

The starting materials listed by means of their formulae in Table 6below were obtained by one or more of the processes described in thepresent specification.

                                      TABLE 6                                     __________________________________________________________________________     ##STR95##                                                                    Example                               Melting point (°C.)              No.  R.sup.19                                                                         R.sup.20   R.sup.18                                                                           R.sub.p.sup.17                                                                     A        or refractive index                     __________________________________________________________________________    XIII-1                                                                             H  CH.sub.3   C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O        n.sub.D.sup.22 = 1.540                  XIII-2                                                                             H  CH.sub.3   CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O        n.sub.D.sup.22 = 1.347                  XIII-3                                                                             H  CH.sub.3   CH.sub.3                                                                           6-CH.sub.3                                                                         O        n.sub.D.sup.22 = 1.552                  XIII-4                                                                             H  CH.sub.3   (CH.sub.3).sub.3                                                                    --  O        52-55                                   XIII-5                                                                             H  CH.sub.3   i-C.sub.3 H.sub.7                                                                  6-i-C.sub.3 H.sub.7                                                                O        96-99                                   XIII-6                                                                             H  C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O        n.sub.D.sup.22 = 1.534                  XIII-7                                                                             H  C.sub.2 H.sub.5                                                                          CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O        n.sub.D.sup.21 = 1.342                  XIII-8                                                                             H  i-C.sub.3 H.sub.7                                                                        CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O        n.sub.D.sup.21 = 1.531                  XIII-9                                                                             H  SCH.sub.3  C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                   ##STR96##                                                                             65-57                                    XIII-10                                                                           H  SCH.sub.2CHCH.sub.2                                                                      C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                   ##STR97##                                                                             n.sub.D.sup.21 = 1.577                   XIII-11                                                                           H                                                                                 ##STR98## CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                   ##STR99##                                                                             viscous oil                              XIII-12                                                                           H  CH.sub.3   CH.sub.3                                                                           3-CH.sub.3                                                                          ##STR100##                                                                            142-143                                 __________________________________________________________________________

It will be understood that the specification and examples areillustrative, but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

What is claimed is:
 1. Method for the protection of crop plants fromdamage by herbicidally active acetanilides of the formula ##STR101## inwhich R is pyrazol-1-yl,X and Y are identical or different and representalkyl with 1 to 4 carbon atoms, Z is chlorine and n represents 0 or 1,and herbicidally active acid-addition salts and metal salt complexesthereof, which method comprises applying to the plants or their habitatan antidotally effective amount of an N-acyl-piperidone ketal compoundof the formula ##STR102## wherein R¹ is a alkyl with from 1 to 4 carbonatoms or chlorine; R² is chlorine; R³ and R⁴ together represent analkylene chain of 2 to 3 carbon atoms; and R⁵, R⁶, R⁷ and R⁸ arehydrogen.
 2. Method as claimed in claim 1 wherein said compound isapplied to an area of agriculture in an amount of from 0.1 to 5 kg perhectare.
 3. Method as claimed in claim 1 wherein said compound isapplied to seed in an amount of 10 to 300 grams per kg of seed. 4.Herbicidal composition comprising a herbicidally active acetanilide ofthe formula ##STR103## in which R is pyrazol-1-yl,X and Y are identicalor different and represent alkyl with 1 to 4 carbon atoms, Z is chlorineand n represents 0 or 1, and herbicidally active acid-addition salts andmetal salt complexes thereof, and an antidotally effective amount of anN-acyl-piperidone ketal compound of the formula ##STR104## wherein R¹ isa alkyl with from 1 to 4 carbon atoms or chlorine; R² is chlorine; R³and R⁴ together represent an alkylene chain of 2 to 3 carbon atoms; andR⁵, R⁶, R⁷ and R⁸ are hydrogen.
 5. Herbicidal composition as claimed inclaim 4 containing from 0.1 to 95% of a mixture consisting of theN-acyl-piperidone ketal compound and the herbicidally activeacetanilide.
 6. Herbicidal composition as claimed in claim 4 containingfrom 0.04 to 1 part by weight of said antidote compound per part byweight of said herbicidally active acetanilide.
 7. Herbicidalcomposition as claimed in claim 4 containing from 0.1 to 0.5 part byweight of said antidote compound per part by weight of said herbicidallyactive acetanilide.
 8. Method of combating weeds comprising applying tothe weeds or their habitat a composition as claimed in claim
 4. 9.Method as claimed in claim 8 wherein the composition is applied at arate corresponding to 0.5 to 5 kg per hectare of said herbicidallyactive acetanilide.
 10. Method for the protection of crop plants fromdamage by herbicidally active acetanilides of the formula ##STR105## inwhich R is pyrazol-1-yl,X and Y are identical or different and representalkyl with 1 to 4 carbon atoms, Z is chlorine and n represents 0 or 1and herbicidally active acid-addition salts and metal salt complexesthereof, which method comprises applying to the plants or their habitatan antidotally effective amount of an N-acyl-piperidone ketal compoundselected from the group consisting of N-dichloroacetyl-piperid-4-oneethylene ketal; N-dichloroacetyl-piperid-4-one propylene ketal;N-α-chloropropionyl-piperid-4-one ethylene ketal;N-α-chloropropionyl-piperid-4-one propylene ketal.
 11. An herbicidalcomposition comprising an herbicidally active acetanilide of the formula##STR106## in which R is pyrazol-1-yl,X and Y are identical or differentand represent alkyl with 1 to 4 carbon atoms, Z is chlorine and nrepresents 0 or 1, and herbicidally active acid-addition salts and metalsalt complexes thereof, and an antidotally effective amount of anN-acyl-piperidone ketal compound selected from the group consisting ofN-dichloroacetyl-piperid-4-one ethylene ketal;N-dichloroacetyl-piperid-4-one propylene ketal;N-α-chloropropionyl-piperid-4-one ethylene ketal;N-α-chloropropionyl-piperid-4-one propylene ketal.
 12. Method ofcombating weeds comprising applying to the weeds or their habitat anherbicidal composition comprising an herbicidally active acetanilide ofthe formula ##STR107## in which R is pyrazol-1-yl,X and Y are identicalor different and represent alkyl with 1 to 4 carbon atoms, Z is chlorineand n represents 0 or 1, and herbicidally active acid-addition salts andmetal salt complexes thereof, and, an antidotally effective amount of anN-acyl-piperidone ketal compound selected from the group consisting ofN-dichloroacetyl-piperid-4-one ethylene ketal;N-dichloroacetyl-piperid-4-one propylene ketal;N-α-chloropropionyl-piperid-4-one ethylene ketal;N-α-chloropropionyl-piperid-4-one propylene ketal.